There is no over the hill... there is no top of the mountain. In reality, we are all climbing all the time. I have come a long way, but I still run into obstacles, find things I can't get over and have to take the long way around. Sometimes people are ahead of me, and sometimes those same people are behind me. We all have set-backs. We all have triumphs.
It's okay to feel like crap sometimes. It doesn't mean there is something wrong... it's just life.